Both Aristotle and Aquinas seem to subscribe to the idea of a mixed constitution as the form of government best disposed to the common good. By "mixed constitution", I mean mixing between Aristotle's classical taxonomy of political government (Kingship, Oligarchy, Democracy). I wonder how do their ideas of "mixed government" differ. For example, for Aristotle in Politics, the mixing is actually to find a mean between the extreme. So he builds his best constitution on the metaphysics of "middle class," which is the mean of the rich and poor. This is not the case in summa theologica by Aquinas, who just chooses one characteristic from each good form of government and combine them. Are there any other dissimilarities between the two? E.g. We all know that Aquinas tries to adapt Aristotlean philosophy to Christian theology. So what role does theology play in Aquinas' mixed government different from that of Aristotle's?

Both Aristotle and Aquinas seem to subscribe to the idea of a mixed constitution as the form of government best disposed to the common good. By "mixed constitution", I mean mixing between Aristotle's classical taxonomy of political government (Kingship, Oligarchy, Democracy). I wonder how do their ideas of "mixed government" differ? For example, for Aristotle in Politics, the mixing is actually to find a mean between the extremes. So he builds his best constitution on the metaphysics of "middle class," which is the mean of the rich and poor. This is not the case in summa theologica by Aquinas, who just chooses one characteristic from each good form of government and combines them. Are there any other dissimilarities between the two? E.g., we all know that Aquinas tries to adapt Aristotlean philosophy to Christian theology. So what role does theology play in Aquinas' mixed government different from that of Aristotle's?